If I googled endocrinologists Pittsburgh a let came up[including MD names and these:
Allegheny Endocrinology Associates 412) 359-3426
UPMC Endocrinology=UPMC Mercy I would try this!!
Pittsburgh Endocrinology
Anything at Carnegie Mellon?

I guess you have to check if they specialize is osteoporosis and also check ratings. Each hospital or private endo dept. should have names to check. It's difficult but not impossible!